Accelerating water evaporation by the addition of an organo-silicon compound

ABSTRACT

A METHOD FOR ACCELERATING WATER EVAPORATION IS DISCLOSED IN WHICH AN AQUEOUS SURFACE IS TREATED WITH AN ORGANOSILICON COMPOUND. AN AQUEOUS SURFACE HAVING AN ORGANOSILICON COMPOUND ON THE SURFACE IS ALSO DISCLOSED. AN EXAMPLE OF THE ORGANOSILICON COMPOUND IS   D R A W I N G

United States Patent ACCELERATING WATER EVAPORATION BY THE ADDITION OFAN ORGANO-SILICON COMPOUND Richard W. Alsgaard, Midland, Mich., assigiorto Dow Corning Corporation, Midland, Mich. No Drawing. Filed Aug. 15,1968, Ser. No. 752,750 Int. Cl. B01d 1/00, 3/34 U.S. Cl. 159-47 25Claims ABSTRACT OF THE DISCLOSURE A method for accelerating waterevaporation is disclosed in which an aqueous surface is treated with anorganosilicon compound. An aqueous surface having an organosiliconcompound on the surface is also disclosed. An example of theorganosilicon compound is 05115 CmHySliH The present invention relatesto a method for accelerating evaporation from aqueous surfaces and to anaqueous body in which the surface carries an evaporation accelerator.

Whereas the conservation of water is very important, there are manyinstances when the presence of water is undesirable. Some land cannot becultivated because it is covered with water. Some land areas coveredwith water could be useful in agriculture, but for the presence of theWater. This land covered with water can be reclaimed by draining oli thewater, but some such areas are too expensive to drain due to thesurrounding terrain. Thus, other means of removing the unwanted waterare desired. Water can be used for cooling purposes by taking advantageof the heat carried away by the evaporating water. Thus, the rate ofevaporation will determine the amount of cooling obtained and if therate of evaporation can be increased the water will provide a lowertemperature due to its higher evaporation rate. Other situations whereit is desirable to have a higher rate of evaporation include,concentration processes, distillations to obtain pure water, and thelike.

Thus, it is an object of the present invention to provide a method foraccelerating the evaporation of water from aqueous bodies. It is anotherobject to provide an aqueous body with an evaporation accelerator. Theseand other objects will become apparent from the following detaileddescription of the invention.

The present invention relates to a method for accelerating waterevaporation comprising dispersing on an aqueous surface, which is incontact with an atmosphere, an organosilicon compound selected from thegroup consisting of P 2v+l (C6115):

(CH SiO(SiO)xSi(CH (OnH n+1)SiOCH(CH (5H. (CHM slz s (CnH n+ )SiOSiH and(CnHnm w e e n has a value of from 12 to 45 inclusive, p has a value offrom 16 to 20 inclusive, x has a value of from 30 to 40 inclusive and Xis selected from the group consisting of a chlorine atom, a hydrogenatom, a hydroxyl radical and a methoxy radical.

The present invention also relates to an evaporation accelerated bodycomprising an aqueous body having on an aqueous surface a dispersion ofan organosilicon compound as defined in the foregoing paragraph.

The surface of an aqueous body is treated such that the definedorganosilicon compounds are dispersed on the aqueous surface. Anysuitable means of causing the aqueous surface to have a dispersion ofthe defined organosilicon compound can be used. The means for dispersingthe defined organosilicon compounds can include, for example, sprayingeither a finely divided solid or liquid on the aqueous surface, formingan organic solvent solution for the defined organosilicon compoundswherein the organic solvent is a volatile organic solvent and thenspraying, pouring or dispersing by pipes on the aqueous surface of theaqueous body and the like.

The aqueous body can be a stationary or changing body. If the aqueousbody is a changing aqueous body wherein the additions or removals ofpart of the aqueous body are from the surface of the aqueous bodyadditional organosilicon compounds should be added as required tomaintain the desired amount on the aqueous surface, in some cases thiswould be continuous additions of the organosilicon compound. Where theremovals from a changing aqueous body do not effect the surface,additions of the organosilicon compound are usually not required.

The organosilicon compounds useful as evaporation accelerators inthepresent invention include those having long chain alkyl radicalsattached to the silicon atom through silicon-carbon bonds. It iscompletely unexpected that these organosilicon compounds wouldaccelerate the evaporation of water. What is even more unexpected isthat not all organosilicon compounds having long chain alkyl radicalswill accelerate water evaporation.

The organosilicon compounds useful as evaporation accelerators includethose having a formula wherein p has a value of from 16 to 20 inclusiveand x has a value of from 30 to 40 inclusive, examples include,

(CH SiO (SiO)ausi CH (CH Si O (Si O )34si(CH 1H3 3 03 )as 3):, ah 0 0)4o (C s)s Da O 0 )m 03, a) s 35 3):

(C H Si0 (Si 0 )3051 (C H3) (CH3)3S1O (SiO)4oSi (CH and IE3 6H (0 119310 (SlO )gosi (CH those having a formula nH1n-H) C a)z wherein n has avalue of from 12 to 45 inclusive, examples include,

C gH 5SiO CH(CH3)2, CuHgySlO CH(OH3)g, CnHsisio 011(011 CmHg SlO CH(CHCmHySlO CH(CH C oHusiO CH(CH3)g 6 02 eHs)2 0 1171310 CH(CH and C45H91Si0CH(CH those having a formula (C nH n+ )Si OSiH wherein n has a value offrom 12 to 45 inclusive and X is Cl, H, OH or -OCH examples include,

The preferred organosilicon compounds are those of the followingformulae wherein n has a value of from 12. to 20 and x is defined above.

The organosilicon compounds can be applied to the aqueous body as singlespecies or as mixtures of any two or more of the above definedorganosilicon compounds.

The organosilicon compounds can be applied in any amount which iseffective in accelerating water evaporation. It is preferred, however,that less than 0.1 g. be applied per square inch of aqueous surface.Usually not more than 0.010 g. per square inch of aqueous surface isapplied for economical reasons and since any greater amount does notsubstantially effect the evaporation rate. Amounts greater than 0.1 g.per square inch of aqueous surface can be used, if desired.

The method of this invention is useful in accelerating the evaporationwhere a drying atmosphere is in contact with the surface of an aqueousbody. The aqueous body can be in an open tank, a ditch, a trough, a pan,a kettle, a bow], a barrel, a dish or a closed vessel with a dryingatmosphere passing through it, or it can be a pond, a lake, a reservoiror a swamp.

By varying the amount of organosilicon compound applied to the aqueoussurface, the evaporation rate can be controlled. By controlling theevaporation rate, specific cooling effects can be accomplished which aredue to the evaporation process. Thus, the present method can be used tocontrol the temperature of an aqueous body under certain conditions.

The evaporation accelerators can best be prepared by the followingmethods. Compounds of the formula can,

(onrrmusix 611, can best be prepared by reacting an a-olefin with in thepresence of a platinum catalyst, such as chloroplatinic acid. Theresulting product has a formula (CnHZn-H)Si0l 6E, The

CaHu

(CnH )SiO1 6H. is mixed with sodium bicarbonate to produce a silanol ofthe formula (CnH -QSiOH 6E. The

(C,,II )SiCl 611, is reacted with lithium aluminum hydride to produce asilane of the formula CsHs n 2u-l-1) 6E, The

is mixed with excess methanol to produce a methoxysilane of the formulan 2n+l) S OCHg Compounds of the formula (C H5) a n zu-ll) a)2 can bestbe prepared by reacting an u-olefin with H(C H SiCl in the presence of aplatinum catalyst, such as chloroplatinic acid. The resulting producthas a formula is then mixed with excess isopropanol and allowed to standfor a period of time, such as 48 hours. After the removal of any excessvolatile by-products or unreacted starting materials, a product of theformula is obtained.

Compounds of the formula (CH3): (CHM (CnHzn+1)Si0SiH can best beprepared by reacting an a-olefin with H(CH SiCl in the presence of aplatinum catalyst, such as chloroplatinic acid. The resulting producthas a formula G|1H2n+l)siC1 The (CHM

(CnH n+1) iCl and H(CH SiCl are mixed and hydrolyzed. To insure thedesired end product, the H(CH SiCl is used in excess such as two molesof H(CH SiCl to one mole of the (C HZM-QSiCI The reaction mixture isdistilled after hydrolysis to recover the product having a formula(CH3): (C3102 (CnH n+1)Si-O-SiH An alternative method is to react onemole of an oz-0l6- fin with one mole of [H(CH Si] O in the presence of aplatinum catalyst to obtain n 2n+1) s)2 M Compound of the formula (CH);SiO(Si0)xSi(CH 611, can best be prepared by reacting a siloxane of theformula H (CH Si0(S iO)xSi(CH 111 with the appropriate a-olefin in thepresence of a platinum catalyst, such as chloroplatinic acid accordingto the method as described in Great Britain specificaiton No. 1,041,870.

The following examples are illustrative only and should not be construedas limiting the invention which is properly delineated in the appendedclaims.

EXAMPLE 1 (A) In a small bottle, 11.0 g. of H(C H (CH )SiCl was placedand then 19.6 g. of octadecene-l and 5 drops of a solution of one weightpercent platinum as chloroplatinic acid in isopropanol was added to thesilane. This bottle was closed and placed in a C. oven After two hoursthe reaction mixture showed no evidence of silicon-bonded hydrogen andthe mixture was allowed to cool overnight. Theoctadecylmethylphenylchlorosilane, (C1 H3q) (C H )(CH )SiCl, wasrecovered from the reaction mixture by distillation under reducedpressure. The refractive index, was 1.4864 for (C18H3'7) (CGHS) 3) Sicl(B) two grams of (C13H3q)(C H5(CH3)SiCl was placed in a small vial anddioxane added as a solvent. To the resulting solution, LiAlH in dioxanewas slowly added causing an evolution of gas and the mixture becamewarm. The vial was loosely capped and allowed to stand overnight. Theresulting mixture was filtered to remove any excess LiAlH and LiCl-AlClThe dioxane was stripped from the solution and the residue was mixedwith water and toluene. The toluene portion was remove any excess LiAlH,and LiCl-AlCl The dioxane calcium sulfate was removed from the toluenesolution by filtering and the toluene was removed by distillation. Theresidue was octadecylmethylphenylsilane,

( m m) (CGHS) 3) H having a refractive index, n of 1.4826.

(C) Sodium bicarbonate was mixed with some of the (C H (C H (CH )SiCl.The resulting mixture was allowed to stand with occasional stirring.Carbon dioxide evolved from the mixture which became warm. The mixturewas dissolved in diethyl ether and the sodium chloride, formed in thereaction, was filtered off. The diethyl ether was evaporated and theresulting product was (C13H37) (C H )(CH )SiOI-I which had a refractiveindex, 11 of 1.4859.

(D) Mixed (C13H37(C H )(CH3)Cicl with methanol and toluene and agitatedthe mixture for two hours. The solvents were then stripped and theresulting product was (C18H3'7)(C6H5) (CH )SiOH which had a refractiveindex, n of 1.4812.

(E) A mixture of 28 g. of alpha-octadecene and 5 drops of a one weightpercent platinum, added as a chloroplatinic acid in isopropanol washeated to 100 C. and then 21.8 g. of H(C H SiCl was added. The reactionmixture was heated for one day at 100 C., however, unreactedsilicon-bonded hydrogen remained, therefore, 10 g. of the octadecene and5 drops of the platinum catalyst were added. This mixture was heated toC. and

5 more drops of the platinum solution were added and heating wascontinued until only a trace of silicon-bonded hydrogen could bedetected. The mixture was then stripped to C. pot temperature at 1 mm.of Hg. The residue of 23 g. was the product of (caHsh l and had arefractive index, n of 1.5223.

The octadecyldiphenylchlorosilane was mixed with a large volume ofisopropanol and allowed to stand for 2 days. The isopropanol was thenremoved by stripping. Isopropanol was again added and allowed to standfor a short period and then was removed by stripping. The product wasoctadecyldiphenylisopropoxysilane and had a refractive index, 11 of1.5090.

(F) A mixture of octadecene-l, H(CH 3) SiCl and chloroplatinic acid washeated in a high pressure bomb. The resulting mixture was distilled anda product collected which was octadecyldimethylchlorosilane. A mixtureof 7 1136 g. of H(CH SiCl and 2070 g. of theoctadecyldimethylchlorosilane was hydrolyzed. The hydrolyzed product waswashed until neutral with a mixture of water and sodium bicarbonate. Theresulting mixture was dis- 8 (6) A 10 weight percent solution of tilledand 1457.2 g. of in diethyl ether, and

(CH3)z (CH3)2 (7) A weight percent solution of OH (OH Si-OSiH 3): 3);

H S'H was recovered. CH3) W81 0 1 (G) The following solutions wereprepared: 10 111 dlethyl On the surface of 100 g. of tap water in seven250 ml. (1) A 4 Welght percent Sohmon of stainless steel cups, 0.2 g. ofeach solution was placed in CIBH" a cup. The amount of silicon compoundon the surface Hmsio si0)3.s1 c1r. 3 0f the water of each cup was 0.02g., except the (3H3 0181137 in diethyl ether. (0119 810 s imfisuonm (2)A 10 weight percent solution of CH9 was 0.008 g. 06115 The surface areaof the water exposed to the atmosphere CisHe cl was 5.9 sq. in. Theresulting assembly was placed in a (3H3 controlled atmosphere of 65%relative humidity and 68 F. The weight of the cup, water and siliconcom- 111 dlethyl ethefpound solution was initially made and thenobserved at 7 time intervals of 1 day, 2 days, 5 days and 7 days. A con-(3) A 10 Welght percent sohmon of trol cup was also placed in thecontrolled atmosphere. The OGHE control was prepared as above, butwithout the silicon CmHmSiH compound solution. Ten Weight percentsolutions of the l following silicon compounds in diethyl ether 'werepre- CH3 pared in diethyl ether. (8) (CH3): (CH3): (4) A 10 weightpercent solution of CHa(CHz)17SiOSiOH C... 3. 5 3 CmHuSiOH C H 7Sl0 CH3I eH5)2 0 H SiOCH 18 37 a 1n diethyl ether. 40 (11) l H (5) A 10 weightpercent solution of 01511 IS|i0-C CH3 CuHs CH3 01811373100113 Thesesolutions (8-11) were used as a comparison to show the unique propertiesof this methd.

a The results below are the weight percentages of Water in diethylether. lost in a given period under the test conditions.

Percent water loss after Percent? 1110113380 1 2 5 over Compound daydays days days control 1 Control 7.3 14.7 35.0 47.2

mHn

2 (CH3) SiO(?iO) Si(CI-I 9.0 20.2 47.9 64.8 37.3

3 C aH ?iC1 12.5 20.7 57.0 74.0 00.8

........ omHmsiH 13.3 28.0 59.3 70.0 07.4

6 O18H37SlOOH3 0.0 10.2 40.7 55.7 18.0

O H SiOCHwHm TABLE-Cntinued 1 0 Percent water loss after- Percentincrease Compound dag day: day day: coi t i l 8 CH CH 8.9 17.3 44.9 65.137.9

CH (CH2)11 iOiH C H; C H;

9 CH CH 4.5 10.4 31.7 44.1 -6.6

CH3(CH2) 7lOi0H C H C H CmHaIiO-C CH 11 Cal-I5 5. 4 12. 1 27. 2 40. 7-13. 7

1811 S i0 0 H 12. C H O 4. 9 l8. 8 29. 4 37. 7

Cl8H37SiOJ CH EXAMPLE 2 EXAMPLE 3 When any of the following compoundsare dispersed on the surface of a pond by spraying in an amount of 0.01g. of the compound per square inch of water surface, the rateevaporation is increased.

C aaHnsiiH ah O msiwmr When any of the following compounds are dispresedon the surface of an insect breeding pool in an amount of 0.1 g. persquare inch, the rate of evaporation increases.

(e) a mixture of 20 parts by weight of cm-msr-o-snr 20 parts by weightof CwHsaSiH and 20 parts by Weight of a)a )aa a)a CeHs Cz H4 S iCl $113(g) a mixture of 40 parts by weight of C H SiH and 30 parts by weight ofThat which is claimed is:

1. A method for accelerating water evaporation comprising dispersing onan aqueous surface, which is in contact with an atmosphere, anorganosilicon compound selected from the group consisting of p zo-u(Col-I5) 93 x C 103, (Cu zn-H) 0 0 a):

(On Zn-H) s -O-siH and (CnHgM-l) 51X wherein n has a value of from 12 to45 inclusive, p has a value of from 16 to 20, x has a value of from 30'to 40 inclusive and X is selected from the group consisting of achlorine atom, a hydrogen atom, a hydroxyl radical and a methoxyradical. a

2. The method according to claim 1 in which the amount of organosiliconcompound per square inch of aqueous surface is less than 0.1 gram.

3. The method according to claim 1 in which the evaporation of thewater, is accelerated by dispersing and maintaining an evaporationaccelerator film of the organosilicon compound on the aqueous surface.

4. The method according to claim 3 in which the amount of organosiliconcompound per square inch of aqueous surface is less than 70.01 gram.

5. The method according to claim 1 in which the organosilicon compoundis in an organic solvent for the organosilicon compound.

6. The method according to claim in which the organic solvent is avolatile organic solvent.

7. The method according to claim 1 in which the organosilicon compoundhas a formula p zv-u (CHa)3 iO(SIiO);Si(CHa)a CH9 8. The methodaccording to claim 7 in which 12 is 18. 9. The method according to claim8 in which x is 35. 10. The method according to claim 1 in which theorganosilicon compound has a formula (CaHs):

n 2n+l) Si 0 0 11): 11. The method according to claim in which n is 18.

12 12. The method according to claim 1 in which the organosiliconcompound has a formula 13. The method according to claim 12 in which nhas a value of from 12 to 20 inclusive.

14. The method according to claim 13 in which n is 18.

15. The method according to claim 1 in which the organosilicon compoundhas a formula 16. The method according to claim 15 in which X is achlorine atom.

17. The method according to claim 16 in which n has a value of 12 to 20inclusive.

18. The method according to claim 17 in which n is 18.

19. The method according to claim 15 in which X is a hydrogen atom.

20. The method according to claim 19 in which n has a value of from 12to 20 inclusive.

21. The method according to claim 20 in which n is 18.

22. The method according to claim 15 in which X is a hydroxyl radical.

23. The method according to claim 22 in which n is 18.

24. The method according to claim 15 in which X is a methoxy radical.

25. The method according to claim 24 in which n is 18.

References Cited UNITED STATES PATENTS 2,486,162 10/ 1949 Hyde 260-44823,138,546 6/1964 Muller 203-10 3,154,460 10/ 1964 Graner et al 14-673,220,934 11/1965 Berejick 203-10 3,279,527 10/ 1966 Hardy 159-473,282,327 11/1966 Hardy et al. 159-47 3,290,231 12/ 1966 Ries et al203-10 3,361,186 1/1968 Wildi et al. 203-10 3,361,645 1/1968 Bodell203-10 3,441,075 4/1969 Wildi et al. 203-10 3,475,282 10/1969 Hamilton159-47 WILBUR L. BASCOMB, JR., Primary Examiner US. Cl. X.R.

159-1S; 23-307; 203-10, DIG. 1; 260-4482

